X-ray technology for some applications, such as detection of explosives and other industrial radiography, requires a relatively small X-ray source device that is easily portable. Although small X-ray source devices are useful, they sometimes lack sufficient capability. In some situations, achieving a required energy level to perform certain X-ray applications using a conventional small X-ray source is not possible. What is needed is an X-ray tube for use in a small X-ray source device capable of operating at higher energy levels.